Portable multimode reverse osmosis water purification system

ABSTRACT

A water purification system is disclosed which, includes a reverse osmosis (RO) system or component that is connectable to a city or other outside water feed that is capable of responding to and compensating for low or no feed water pressure coming into the RO system to ensure the outgoing supply of purified water is provided consistently and at a minimum water pressure. This can be accomplished without the need for communication with another device or system-wide facility, such as a hospital, or a pharmaceutical or semiconductor manufacturing system, requiring a constant water supply.

CLAIM OF PRIORITY

This application claims priority to and the benefit of U.S. Provisionalapplication with Ser. No. 62/573,461, filed on Oct. 17, 2017, entitledPORTABLE MULTIMODE REVERSE OSMOSIS WATER PURIFICATION SYSTEM, which isherein incorporated by reference in its entirety.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application relates to U.S. Patent Publication No. 2014/0151297,filed on Nov. 27, 2013, and entitled “Portable Reverse Osmosis WaterPurification System,” the disclosure of which is incorporated byreference.

TECHNICAL FIELD

The present disclosure relates to water purification systems. Morespecifically, the present disclosure relates to a portable or installedreverse osmosis water purification system requiring a steady andreliable city feed water supply.

BACKGROUND

Reverse osmosis (RO) is a filtration method that removes many types oflarge molecules and ions from solutions by applying pressure to thesolution when it is on one side of a selective membrane. More formally,RO is the process of forcing a solvent from a region of high soluteconcentration through a semipermeable membrane to a region of low soluteconcentration by applying a pressure in excess of the osmotic pressure.The result is that the solute is retained on the pressurized side of themembrane and the pure solvent is allowed to pass to the other side. Themembrane is selective in that large molecules or ions are not allowedthrough the pores in the membrane, but allows smaller components of thesolution (such as the solvent) to pass freely. RO filtration has variousapplications, including drinking water purification, wastewaterpurification, food industry uses (e.g., for concentrating food liquid),and health care uses (e.g., dialysis systems).

Installed or portable RO systems or other water purification systems areused for providing pure water to a dialysis machine, a medical facilityor to a pharmaceutical or a semiconductor manufacturing facility where aclean reliable, uninterrupted water supply is necessary. Interruptionsin clean water supply can lead to medical treatment lag times orcancellations or can lead to the contamination of or the impropermanufacturing of expensive pharmaceutical or semiconductor products. Insome cases, the external water supply provided by the city or town maylack sufficient pressure to reach higher floors in a building or canexperience fluctuations due to other city users leading to interruptionsin the water supply. The challenges are even greater where portable ROmachines are being used which are incapable of operating with zero orvery low water pressures.

It would be highly advantageous to the market to provide a portable orstandalone RO system or water purification system with the capability tocompensate for disruptions in city or facility water supply pressure orlow water pressure and in some cases no water pressure for an extendedtime to avoid disruptions in medical treatment or sensitive productmanufacturing. Further, it would also be advantageous to be able torespond to external water supply interruptions without the need tocommunicate or coordinate with the operator or the devices and systemsconnected to the water purification system.

SUMMARY

In one example embodiment, there is provided a system for maintaining aconstant water supply from an external widely pressure fluctuating feedwater supply, the system includes a reverse osmosis (RO) system having afirst water inlet and a second water inlet sourced from a two-valvesplit coupled directly to an external feed water supply, the secondwater inlet directing the external water supply through an internalstorage tank, the first and second water inlets terminating at a commonfeed supply for a pressurizing pump, the at least one pressurizing pumpadapted to receive water primarily from the internal storage tank andalternatively from the external feed water supply, the pump configuredto provide water to a RO membrane unit and deliver purified waterthrough a delivery conduit to an external device or system. The systemfurther includes a first solenoid valve coupled between the first waterinlet and the pump inlet of the at least one pressurizing pump, thefirst solenoid valve operable as a function of the feed water pressurein the storage tank. The system also includes a second solenoid valvecoupled to the second water inlet between the external feed water supplyand the internal storage tank, the second solenoid valve controllable asa function of a feed water pressure in the storage tank, wherein anoutlet of the tank is coupled to an inlet of the pump. The systemfurther includes a controller module including an operating programconfigured to monitor and measure feed water pressure and water levelswithin the internal storage tank and the external water supply, whereinthe controller module is configured to open the first solenoid valve toallow a flow of external feed water to the pump inlet upon sensing thefeed water pressure from the storage tank dropping below a predefinedlevel and wherein the controller module is configured to increase a pumprate of the pressurizing pump so as to form a suction force on theexternal feed water supply upon a drop in an external feed waterpressure below a predefined level The system in addition includes atleast one storage tank water level sensor system communicatively coupledto the controller module and configured to measure water stored withinthe internal storage tank so as to maintain the water level to apredetermined fill level. In a related embodiment, further comprising athird solenoid valve coupled to a return port of the RO system andresponsive to a signal from the controller module for directing water tofill the internal storage tank using the external feed water supply. Ina related embodiment, upon receiving a signal from a level sensor of thestorage tank that the tank is filled, the controller sending a signal tothe pump to cease and signaling the first solenoid valve to close andcease the flow of the external feed water supply. The system alsoprovides for a pure water flow path configured to allow unused purifiedwater to return via a flow into the internal storage tank.

In various related embodiments of the system, upon receiving a signal ofan increase of the feed water pressure of the storage tank is above apredefined level, the controller module provides a signal to close thefirst solenoid valve and signals the pump to decrease the pump rate tothe RO membrane. In a related system, the controller module includes aheat forward sanitizing program configured to control the heatingelement and an integrated temperature sensor to sanitize an externaldevice coupled to an output port of the system. In yet another relatedsystem, a waste water flow path configured to allow waste water from theRO membrane to be combined with unused purified water to return via aflow into the internal storage tank.

In another example embodiment, there is provided a method formaintaining a constant water supply from an external feed water supplyto an external device or system, the method including the steps ofproviding an RO system having an internal storage tank for providingwater to an external device and utilizing an internal pump to providethe water from the storage tank to the external device and monitoringthe internal storage tank to ensure a water supply pressure and waterlevels are at predefined levels. Next, the method includes initiatingvia a controller a flow of water from an external feed water supply uponopening a first solenoid valve and using the internal pump when waterlevels and pressure from the storage tank are below predefined andclosing a second solenoid valve coupled to the external feed watersupply. The method further includes the step of directing external feedwater to the RO system through an RO membrane to the external device. Ina related embodiment, the method further includes the step of increasinga pump rate of the pressurizing pump so as to form a suction force onthe external feed water supply upon a drop in the external feed waterpressure below a predefined level.

In related embodiments, the method includes one of: a) directly fillingthe internal storage tank using the external feed water supply inresponse to a signal from the controller and a storage tank sensorsystem; b) automatically closing the first solenoid valve and decreasingthe pump rate of the pressurizing pump upon sensing an increase of thefeed water pressure above a predefined level in the storage tank; and c)closing the first solenoid valve and isolating the internal storage tankand solely using the storage tank water for RO functions after openingthe second solenoid valve. The method further includes a purge functionthat includes directing feed water to the RO system only includes waterfrom the storage tank during a purge function of the RO system. Themethod also includes a cooling function in which the step of cooling theRO system is performed by directing one of feed water from the storagetank or the external feed water supply.

In related example embodiment, there is provided a system formaintaining a constant water supply from an external feed water supply,the system including a water purification system that is not necessarilylimited to chemical purification and is not limited to controlling theflow of water in a system. The teachings provided herein can apply tocontrolling fluid flow in other systems and applicable to other fluids.

While multiple embodiments are disclosed, still other embodiments of thepresent invention will become apparent to those skilled in the art fromthe following detailed description, which shows and describesillustrative embodiments of the invention. Accordingly, the drawings anddetailed description are to be regarded as illustrative in nature andnot restrictive.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic view of an embodiment of a RO based waterpurification system providing a sustained, uninterrupted purified watersource for various applications.

While the invention is amenable to various modifications and alternativeforms, specific embodiments have been shown by way of example in thedrawings and are described in detail below. The intention, however, isnot to limit the invention to the particular embodiments described. Onthe contrary, the invention is intended to cover all modifications,equivalents, and alternatives falling within the scope of the inventionas defined by the appended claims.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the FIGURES, FIG. 1 illustrates a schematic view of anembodiment of a RO based water purification and supply system thatprovides a sustained, constant purified water source for variousapplications. In other embodiments, the water purification system ischemical or heat based with the teaching herein not being necessarilylimited to RO systems for water purification. In this exampleembodiment, a multimode water supply system 100 purifies water providedby a city or township feed water supply 110 for use in variousapplications, such as hemodialysis, other medical treatments or use inmanufacturing systems needing a reliable uninterrupted clean watersupply. System 100 provides processes for monitoring for feed waterpressure, feed water quality, feed water temperature, pump outletpressure, product (or purified) water pressure, product (e.g., purified)water temperature, product water quality and, when desired, membraneperformance (percent rejection). In this example embodiment, a variablefrequency pump 120 provides the pressure required to push water througha RO membrane 140 and against a fixed orifice. Fluid controls (solenoidvalves, check valves, and temperature and pressure sensors) along with acontroller module 160 provide a means of managing flow rates andpressures.

Although, RO based multimode water supply system 100 can provide forsanitizing with heated purified water, in this particular embodiment thefocus of the invention described herein is to provide a reliable watersource for normal dialysis operation from a good feed pressure watersource (such as storage tank 180) or to sustain such dialysis operationfrom a poor feed pressure alternative flow that includes directlydrawing water from a city feed such as city feed 110. Water supplysystem 100 includes having a first inlet 112 that splits off to a secondinlet 113 for providing potable water to storage tank 180 from anexternal (city) potable feed water supply 110. System 100 furtherincludes a pressure regulator 114 and a solenoid valve assembly 116coupled to the city water supply at first water inlet 112 and a solenoidvalve assembly (SV6) 185 coupled to second water inlet 113, bothsolenoid assemblies being communicatively coupled to controller module160. An internal storage tank 180 is provided for storing purified waterand is the main/primary source of water for the multimode water supplysystem. Water supply system 100 has at least one RO membrane unit 140(or any other water purification subsystem) that receives water frompotable feed water supply 110 and which purifies the water and deliversthe purified water through a delivery conduit 142 and eventuallyprovides purified product water at product/purified water outlet 150.System 100 also includes a return outlet 170 for directing excess orunused product water to either storage tank 180 or to a drain outlet130. In this example embodiment, drain outlet 130 can also receive wastewater from membrane 140 via conduit 141 and through solenoid valve (SV2)126 and solenoid valve (SV4) 128, having a single coil such that anormally closed (NC) part of the valve is closed (no electricityprovided) and directs the water to drain 130. When the normally closed(NC) portion of the solenoid valve is open (energized electrically bysignal from controller 160), then water is directed to tank 180. Thenormally open (NO) portion of solenoid valve 128 is in a fail-safe modeof being open. The drain output 130 may be connected to a receptacle orother system for proper disposal of the drain fluid.

In this example embodiment, multimode water supply system 100 can usecontroller module 160 to provide several functions including activatinga heat or chemical sanitizing cycle within the water supply system, andthat is also programmed to operate the various components of the system100 and controls the various solenoid, quality/temperature sensors andcheck valves that control water/fluid flow in system 100. Optionally,controller module 160 further includes a heating power managementcontrol circuit to drive heated sanitized purified water solely throughthe water supply system. The system described herein provides variousadvantages including but not limited to addressing issues of low ROsystem water pressures and low external city feed water pressures; theability to switch from break tank mode (storage tank usage only) toexternal feed or city water and then switch back again automatically;and being able to operate the disclosed system even down to levels of nowater pressure or supply from the external source without damaging thebasic RO system. System 100 also advantageously is able to isolateportions of the internal systems unlike central RO systems such as beingable to automatically shut off the storage tank system using solenoidvalves or shutting off the city feed source using the solenoid valvewhen the external city feed is no longer needed. The increase solenoidvalve and check valve count along with the additional pressure andtemperature sensors, working in conjunction with controller 160, allowsfor precise control of specific flows within system 100. For instance,the addition of solenoid valve SV6 allows for direct feeding or fillingof the storage tank 180 only. The switching valves in system arehardwired with controller 160 but it is within one skilled in the art toreconfigure the solenoid valves to include wireless communicationmodules to facilitate wireless communication with controller 160 orother system-wide or network controllers that may operate wirelessly orin a network configuration.

Referring again to FIG. 1, in this example embodiment of multimode ROsystem 100 there is included a series of solenoid valves (SV), checkvalves (CK) and conductivity sensors (Q) that are housed in mainmanifold 115 to facilitate precise control of not only heating andcooling flows throughout the RO system as well as a heat forward processbut also the multimode sourcing of product water being supplied to thedialysis machine as described herein. Solenoid valve (SV1) 116 is arinse water solenoid that is a normally closed valve used during thepurge, rinse and the heat forward process. It is also open if there isnot enough water in the internal water tank 180 during normal dialysisoperation. Solenoid valve (SV2) 126 is a waste water valve assembly thatincludes two solenoids. During normal dialysis operation SV2a is closedand water flows through the orifice hole. The valve is open duringflushing, chemical and heat disinfection processes. Solenoid valve SV2bopens during the heat forward process to provide a specific amount ofbackpressure on the membrane. Solenoid valve (SV3) 122A is a productwater solenoid that is normally closed. During startup, the water flowis diverted and once the product water quality improves below a productwater quality alarm, it opens and supplies water to the product line andproduct outlet 150. Solenoid valve (SV4) 128 is a waste recycle controlsolenoid which is a 3-way valve that directs waste flow to the drain 130of RO system 100. This solenoid valve can also recycle waste water intointernal tank 180 when the RO system is set up for a water saverfunction for re-use or re-application later (see upper path 143 arrowdirected towards tank 180) when its coil is energized via a signal fromcontroller 160. Solenoid valve (SV5) 172 is a product water returnsolenoid valve having two solenoids (having NC and NO functions): a)solenoid SV5a provides backpressure during normal operation of the ROsystem allowing it to supply product water at a pressure ofapproximately 30 psi and during heat and chemical modes, this valve isopen by pressure mechanically allowing full flow for proper operation,but can also be opened by energizing the coil from a signal receivedfrom controller 160; and b) solenoid SV5b, which has to be energized(via a signal from controller 160), allows product water to flow to tank180 or direct to drain 130. Finally, solenoid valve (SV6) 185 is aninlet water solenoid valve which provides feed water to the internaltank 180 from city feed 110 during operation of the RO system duringchemical rinse, heat forward and normal dialysis processes (should waterpressure from water sourced at storage tank 180 drop substantially).

Referring again to FIG. 1, a series of check valves are provided thatoperate with the various solenoid valves and controller 160 to controlthe various flows for various processes including the multimode watersupply process described herein. A check valve (CK1) 130, which islocated on the waste side of the membrane 140 along conduit 141,provides backpressure during certain processes including the heatforward process. A check valve (CK2) 174, which is located between thedrain line 130 and solenoid valve (SV5) 172, prevents waste water fromentering the product line 150. A check valve (CK3) 132, which is locatedbetween the internal tank 180 and drain 130, will divert water to thetank if the drain line is obstructed. A check valve (CK5) 184, which islocated in the tank outlet path to the pump 120, prevents city feedwater 110 from being fed into internal tank 180.

RO system 100 also includes a series of conductivity sensors (Q) whichare in communication with controller 160 as well as the solenoid valvesand check valves to control flows within system 100. An RO feed waterconductivity sensor (Q1) 118 monitors the quality and temperature of theinlet water to pump 120 is a temperature compensated sensor. Inlet waterquality and temperature can be viewed from an ANALOG screen on the ROsystem display/GUI (user interface). This value is compared to theproduct water quality reading to calculate the percent rejection. Aproduct water conductivity sensor (Q2) 122C monitors the quality andtemperature, with temperature sensor 122B, of the water after it exitsthe membrane 140. Product water quality can be viewed from a RUN screenduring normal operation and this value is compared to the inlet waterquality reading to calculate the percent rejection. Temperature can alsobe viewed from the ANALOG screen of the RO system 100 display and thistemperature sensor 122B is also temperature compensated. An RO feedwater pressure sensor (PS1) (near regulator 114) monitors the incomingwater pressure to the RO system 100 and will shut down the RO system ifthere is low or high RO feed water pressure. The feed water pressure canbe viewed from the ANALOG screen. A pump outlet pressure sensor (PS2)124 monitors the output of the pump 120 and will shut down the RO systemif an overpressure or under-pressure condition is sensed. The pumpoutlet pressure can be viewed from the RUN screen of the system displayand pump pressure can also be viewed from the ANALOG screen. A productwater pressure sensor (PS3-near return 170) monitors the product waterpressure and will shut down the RO system if an overpressure conditionis detected. The product water pressure can be viewed from the RUNscreen or from the ANALOG screen. A pressure regulator (PR) 114 controlsthe incoming feed pressure to the RO system when solenoid valve (SV1)116 is open. A flow sensor (FS1) 193 monitors the flow of product waterfrom the membrane 140, thereby displaying flow on the RUN screen or theANALOG screen. A thermocouple (TC/F) 191, which is located near heater190, monitors the temperature of the water exiting heater 190. Thetemperature is displayed on the RUN screen and can also be viewed fromthe ANALOG screen.

In this example embodiment, system 100 includes at least onepressurizing pump 120 adapted to receive water from one of: a) thestorage tank 180, while the system is operating a break tank mode withsolenoid valve 185 being the primary water source (primary mode); or b)from city feed water inlet 112 via solenoid valve 116 which is the lowor zero pressure feed source that provides water to a RO membrane unit140 should the water pressure be insufficient from storage tank 180(meaning water levels may be very low and pure product water is notbeing produced fast enough), thereby delivering purified water through adelivery conduit 142 to an external device (e.g., dialysis machine) orsystem requiring a constant water supply of purified water. When wateris drawn via valve 116 from city feed 110 as the alternate source in thenormal run mode for the dialysis machine, check valve 184 followspressure conditions set by the state of valve 116 to close this path.Controller module 160 includes an operating program that monitors theinternal water pressure from storage tank 180 while in break tank mode,and monitors external feed water pressure provided by city feed 110,analyzing water levels via level sensors 181, 182 and 183 withininternal storage tank 180. While in the normal dialysis run mode andwith good feed pressure, the primary water source is from city feed 110through solenoid valve 185 via line 113 and through storage tank 180.Water then flows through check valve 184 and then to inlet 117 of pump120 to be pumped through membrane 140 and out to product outlet 150.Hence, in the primary operating mode, where there is adequate city feedpressure, city water enters the tank to a controlled set ofpredetermined level points. A volume of raw city water is then consumedby a suction at the inlet of pump 120 as it supplies membrane 140 withpressurized water for the production of purified product water. In themeantime, system 100 attempts to fill the water level in tank 180 andattain water levels between the predefined level set points measured bythe level sensors (LS).

When system 100 is in the normal dialysis operating run mode and waterpressure runs low or there is poor feed pressure (such as from tank180), an alternate water source is provided from city feed 110 viasolenoid valve 116 through line 112 through to inlet 117 of pump 120.Pump 120 then begins to draw water from city feed 110 if the pressure istoo low so as to stabilize the water flow and pressure going to membrane140. Check valve 184 closes once solenoid valve (SV1) 116 opens as itresponds to feed pressure conditions, automatically without the need fora direct signal from controller 160, as check valve 184 (as all checkvalves in the system) is a passive component. In this current mode(non-break tank mode), controller module 160 also initiates an increasein a pump rate of the pressurizing pump 120 so as to form a suctionforce on the external feed water supply 110 upon a drop in the city feedwater pressure below a predefined level or a drop below a predefinedlevel at storage tank 180. Water is then being drawn via suction fromcity feed 110 from pump 120 responsive to a signal from controller 160and from the storage tank level sensors to directly fill the internalstorage tank 180 using external feed water supply 110 as water is beingsupplied to membrane 140 if there is enough water to conduct bothoperations. Storage tank 180 begins to refill though solenoid valve 185via line 113 and once storage tank 180 is filled to level 1 (LS1) ofsensor 181, controller 160 switches system 100 back to break tank modeand shuts down pump 120 from drawing water directly from city feed 110.The level of the fluid in internal tank 180 is measured by the levelsensors 181, 182 and 183. The level sensor 181 is triggered when waterin tank 180 is at or above a maximum water level, level sensor 182 istriggered when water in tank 180 is at or below an intermediate waterlevel, and the level sensor 183 is triggered when the water in tank 180is at or below a minimum water level. Hence, in the second operatingmode, where there is an inadequate city feed pressure and city water isentering tank 180 but the tank level is unable to reach beyond a setpoint for a period of time or the tank level remains at the lowest pointwith the tank supply valve open, feed water is then supplied directly tothe pump inlet 117 with this second operating mode canceling out uponthe tank level of tank 180 recovering or reaching its normal maintainedpreset water levels of the primary mode of operation of system 100.

In a third operating mode, pure product water is collected during apurge function of RO system 100. In this mode, city feed water isdirected to inlet 117 of pump 120 to supply water to membrane 140. Purewater coming from membrane 140 is then directed and stored in tank 180for other process uses, such as for purging membrane 140 and flowingpure product water through critical RO flow paths prior to entering aself-heat disinfection mode or chemical application mode. During a purgecycle, storage tank 1800 is emptied and no city feed water flows intothe tank, hence solenoid valve 185 and solenoid valve 116 are closed.Thereafter, storage tank 180 is refilled with only pure water sourcedfrom city feed water 110 via solenoid valve 116 through to inlet 117 ofpump 120. Water then flows from membrane 140 through delivery conduit142 through product outlet 150 and it returns to return inlet 170 totank 180 via line 170A. Advantageously, a single pump 120 in this systemprovides the various functions including reverse osmosis watergeneration and directing pure product water from either the storage tankor the city feed in low pressure situations. Upon purging the entiresystem 110, pure product water from storage tank 180 is used such thatthe water flows through check valve 184 through pump inlet 117 and thewater is pumped by pump 120 through membrane 140 and then throughconduits 141, 143 and 145 and out to drain 130. Check valve 184 is at anoutlet of tank 180 and prevents pump 120 feed water from being fed backinto tank 180. The other part of system 100 is purged as water frommembrane 140 flows through conduit 142 out to product outlet 150 andreturns to return port 170 through solenoid valve 172 and then throughcheck valve 174 before going out to drain 130. Check valve 174 isconnected between drain output 130 and is configured to relieve pressurein the drain line when the drain output 130 is not connected or notfunctional. A solenoid valve 185 is controllable to prevent backflow ofwater in internal tank 180 into city feed water input 110 during thepurge cycle. These disinfection and chemical application processesactually have better outcomes when performed with high grade productwater as described above.

In a fourth operating mode, and while RO system is operating in eitherthe first or second modes, RO concentrate or waste water and/or unusedproduct water can be combined and stored in tank 180 for eventualreprocessing through membrane 140. This fourth operating mode providesthe advantages of the recovery and re-application of unused water whileoffering some level of water consumption efficiency over time. In afifth operating mode, the volume of water in tank 180 is isolated andthen is consumed by RO system 100 as it flows to various outlet pointsto drain 130. In this operating mode the tank is emptied and madeavailable for pure water storage of the third mode and other processes.

In summary, the multimode system 100 described herein provides theadvantages of supplying dialysis grade water at adequate flows with zerocity feed pressure applied as long as the feed water supply is availablefor suctioning by pump 120 (as if being supplied from tank 180 while inthe break tank mode). Poor city feed conditions are too often the casein hospital facilities nationally and internationally (and even otherindustrial facilities such as in pharmaceutical or semiconductor deviceproduction), hence this provides a solution and an substantial advantagein continuing to provide water to a desired consumption point or processwithout disrupting the patient treatment (or production) and withoutinvesting in infrastructure equipment to increase water production atthe point of the water source coming into the facility.

System 100 further includes a waste diverting valve 127 which allowswater flow via 143 into one of the internal storage tank 180 (upperpath) and a (lower path) waste path 145 to external drain 130. A purewater flow path 170A from return outlet 170 allows unused purified waterto return via an inlet flow 171 into the internal storage tank 180.System 100 further includes a water product return solenoid valve 172,via check valve 174, coupled to drain outlet 130 and communicativelycoupled to the controller module, which facilitates the drainage ofstorage tank 180.

The increased solenoid valve count of system 100 also provides theadvantage of rapid cool down of the RO system as cool water can be addedto the system from either storage tank 180 or from city feed 110. Thereis also more precise control of the waste water function due to thevarious check valves incorporated into the system working with thevarious solenoid valves. There is now a hard flow path that isconfigured from membrane 140 to drain 130 to dispose of waste water morequickly and efficiently. Further, due to the improve flows and pressureand measurement of such flows, system 100 can heat up more quickly andreach target heat temperatures taking the time down from three (3) hoursin prior art systems to one (1) hour in system 100, depending on thetemperature of the incoming water being supplied to system 100. Hence,this allows for single self-heat disinfection of the RO system withoutthe use of chemicals to disinfect the RO system. When system 100 is in aheat storage mode, system 100 can be cooled down more quickly beforepatient use due to the capability of controlling flows within system100. Finally, if chemicals were used in the RO system for cleaning anddisinfection, such can be flushed out through drain 130 faster due todirect valve control by controller 160 (and the associated solenoidvalves).

In this example embodiment, system 100 also includes a variablefrequency drive (VFD) pump 120 that is coupled to an RO membrane unitinlet 139 and that is communicatively coupled to controller module 160.Pump 120 generally controls the fluid pressure through system 100 andgenerally controls water pressure input to membrane 140. In someembodiments, pump 120 maybe a pump other than a VFD pump and has a pumppressure of about 160-200 pounds per square inch (psi) (1.10-1.24 MPa).In some embodiments, a pump includes a pressure sensor used to controlthe operation of VFD pump 120 so as to shut down system 100 if anoverpressure condition is detected. In this example embodiment, VFD pump120 is designed to operate at a first pumping rate until an averagewater supply temperature and pressure (provided by tank 180) isdetermined and once an appropriate predefined temperature and pressureis achieved then transitioning to a second pumping rate. VFD pump isfurther designed to draw water from city feed 110 to stabilize VFD pump120 from low levels of water in tank 180 and to maintain water flow andsupply to the connected device or dialysis machine.

In a related embodiment, system 100 further includes a heating elementresponsive to the controller module configured to assist with a heatsanitizing function of the RO system components, wherein the controllermodule includes a heat forward sanitizing program configured to controlthe heating element and an integrated temperature sensor to sanitize anexternal device coupled to an output port of the system.

Various embodiments of the invention have been described above forpurposes of illustrating the details thereof and to enable one ofordinary skill in the art to make and use the invention. The details andfeatures of the disclosed embodiment[s] are not intended to be limiting,as many variations and modifications will be readily apparent to thoseof skill in the art. Accordingly, the scope of the present disclosure isintended to be interpreted broadly and to include all variations andmodifications coming within the scope and spirit of the appended claimsand their legal equivalents.

1-9. (canceled)
 10. A method for maintaining a constant water supplyfrom an external feed water supply to an external device or system, themethod comprising the steps of: providing an RO system having aninternal storage tank for providing water to an external device andutilizing an internal pump to provide the water from the storage tank tothe external device; monitoring the internal storage tank to ensure awater supply pressure and water levels are at predefined levels;initiating via a controller a flow of water from an external feed watersupply upon opening a first solenoid valve and using the internal pumpwhen water levels and pressure from the storage tank are belowpredefined; closing a second solenoid valve coupled to the external feedwater supply; and directing external feed water to the RO system throughan RO membrane to the external device.
 11. The method of claim 10further comprising the step of increasing a pump rate of thepressurizing pump so as to form a suction force on the external feedwater supply upon a drop in the external feed water pressure below apredefined level.
 12. The method of claim 10 further comprising the stepof directly filling the internal storage tank using the external feedwater supply in response to a signal from the controller and a storagetank sensor system.
 13. The method of claim 10 further comprising thestep of automatically closing the first solenoid valve and decreasingthe pump rate of the pressurizing pump upon sensing an increase of thefeed water pressure above a predefined level in the storage tank. 14.The method of claim 13 further comprising the step of closing the firstsolenoid valve and isolating the internal storage tank and solely usingthe storage tank water for RO functions after opening the secondsolenoid valve.
 15. The method of claim of claim 10 wherein the step ofdirecting feed water to the RO system only includes water from thestorage tank during a purge function of the RO system.
 16. The method ofclaim 10, further comprising the step of cooling the RO system bydirecting one of feed water from the storage tank or the external feedwater supply.